I have made a dedicated L4D2 server, It is linked with a group.
I ( and other people, so its not a port/firewall problem) can connect the following ways :

- steam group server
- Manual IP connect

All works fine.

But when I start a lobby, and set it to best available dedicated, It will search for a while and say that it cant find one ( or randomly decides to use another one )
So I read on these forums that I should use the following command :
mm_dedicated_force_servers xx.xx.xx.xx:xxxx
So I do, start a lobby and when trying to connect to the server, It again does not work.

When I switch best available dedicated to steam group server in the lobby, it also cant connect.

server.cfg

Code:

/-----------------------------------------------------------
//--> This server.cfg is custom-created to assist server owners with
//--> setting up their server.cfg. You can copy/paste this text
//--> into your server.cfg or simply cookie cutter and use the
//--> parts that you would like to.
//-----------------------------------------------------------
//--> Updated 01/04/2010
//-----------------------------------------------------------

//--> Do not connect to the Match Making Service
//--> "0" = Off
//--> "1" = On
sv_steamgroup_exclusive 0

//--> When Enabled, Steamgroup members take priority when joining
//--> The server. However, anyone may join as long as a steamgroup
//--> Member has joined first. Slots are only reserved while they
//--> Are available in this manner, and a minimum of 1 slot is
//--> Reserved, because when a steamgroup member connects to the
//--> Server, other players will be able to connect. If there are
//--> Other players connected and the steamgroup member disconnects
//--> A random player will qualify to fill the remaining slot.

sm_cvar director_super_weapon_density 0.0
//--> How much super weapons (Grenade Launcher, etc.)
//--> should there be for every 100 sq ft in each level.

sm_cvar director_tank_force_offer 1
//--> Force the director to spawn a tank on each level.
//--> Remember, the director can only force a tank spawn
//--> On levels that have "possible" spawn locations already.
//--> There are some levels that do not have tank spawn
//--> Locations, and as a result, this does not work on all levels.

sm_cvar director_tank_lottery_selection_time "2"
//--> How many seconds the tank waits to give an infected
//--> Player control of the Tank. During this interval
//--> The AI controls the Tank.
//--> Default "4". Set to "0" to remove AI control completely.

sm_cvar z_ghost_delay_max 22
sm_cvar z_ghost_delay_min 22
//--> Maximum/Minimum amount of time (in seconds) for players to
//--> Wait to respawn as the Infected.
//--> Ex: Min/Max both = "22", Infected will ALWAYS have a 22
//--> second spawn timer. If Max = "22" and Min = "15", the
//--> Spawn timer will be random, between 15 and 22 seconds.

//-----------------------------------------------------------
//--> There are some items such as medpacks & Defibrillators
//--> that are "static" items in each level. Restricting their
//--> Density to "0.0" will remove all non-static items of its
//--> Kind. There is an plugin that will fix this, but removes
//--> All medpacks including starting medpacks, among other
//--> Things.
//--> This plugin is Confogl. Check it out at
//--> http://code.google.com/p/confogl/
//-----------------------------------------------------------

//--> Description:
//--> Download at http://forums.alliedmods.net/showthread.php?p=830069
//--> Allows you to raise/lower player limitations per team
//--> which is normally restricted to "4".
//--> Requires SM 1.3+

//--> Description:
//--> Download at http://forums.alliedmods.net/showthread.php?t=94415
//--> Removes the "maximum" player limit in the server after
//--> players connect from the lobby.
//--> Survival is 4, Versus is 8, etc.
//--> Use in conjunction with servers running >=9 player slots.

l4d_unreserve_full 1
sm_cvar l4d_unreserve_full 1

//--> Set to "1" to automatically unreserve server at "full"
//--> Again, this is 4 for Survival, 8 for Versus, etc.
//--> Set to "0" to require admin to manually enter command.
//--> Type sm_unreserve in console as Admin in-game to
//--> Manually remove the reservation, after the game starts
//--> From the lobby.

//--> Description:
//--> Download at http://forums.alliedmods.net/showthread.php?t=102052
//--> Removes the "maximum" player limit in the server after
//--> players connect from the lobby.
//--> Survival is 4, Versus is 8, etc.
//--> Use in conjunction with servers running >=9 player slots.

sm_heartbeat_auto 1
//--> Makes everyone on the server "heartbeat" when a player
//--> Disconnects. Default: 1 (Enabled.) 0 to Disable.

sm_heartbeat_timeout 20
//--> This is the timeout value between when the command can
//--> be sent.

Still geting the bogus payload data when I try to connect,
setting sv_lan 0 in the server CFG also does not show results.

Wondering if anyone else is having problems with his/her server.
I got it working ( I think ) before the L4D2 update this weekend.

Thought it was a NAT problem, but if people (everyone?) can connect trough connect IPORT // or when I set it to a steamgroup I made, people can connect in the group browser. But I dont think it could be a NAT problem because it works in this way.

Slowly going insane here.

Edit :
After reading and reading and even some more reading on this forum, I understand that hosting a server on a home connection is not a good idea, and yes - My idea is not good. But it should work. It works for CS,CSS,NS and even > L4D2 (non lobby mode)
So

Could it be that :
- mm_dedicated_force_servers externalIP:port
- Connecting to the lobby
- Failing because my router is not correctly looping?
Seems to me that mm_dedicated_force_servers INTERNALIP:xxx wont work at all, if I am not mistaken. Ill try this when I get back home tonight, but doubt it will work.

Still geting the bogus payload data when I try to connect,
setting sv_lan 0 in the server CFG also does not show results.

Wondering if anyone else is having problems with his/her server.
I got it working ( I think ) before the L4D2 update this weekend.

Thought it was a NAT problem, but if people (everyone?) can connect trough connect IPORT // or when I set it to a steamgroup I made, people can connect in the group browser. But I dont think it could be a NAT problem because it works in this way.

Slowly going insane here.

Edit :
After reading and reading and even some more reading on this forum, I understand that hosting a server on a home connection is not a good idea, and yes - My idea is not good. But it should work. It works for CS,CSS,NS and even > L4D2 (non lobby mode)
So

Could it be that :
- mm_dedicated_force_servers externalIP:port
- Connecting to the lobby
- Failing because my router is not correctly looping?
Seems to me that mm_dedicated_force_servers INTERNALIP:xxx wont work at all, if I am not mistaken. Ill try this when I get back home tonight, but doubt it will work.

I'm also going a bit crazy on this, I have the same problem as you. I got it to work a few times after countless tries, very rare occasions to start with people a versus game and a campaign game. Like last night I played a versus game and I started with 8 people just fine. My internet is very good thus everyone had a ping of 30-50. It's frustrating because it can't seem to be able to start a game even though there are things going on in the console when I hit Start the game. So my lobby does communicate with my server, but there's something going on that restrains it from actually starting the game.

I just dislike Valve's servers as they are mostly unstable and laggy. I don't like hosting Local because then I have to make sure to stay in the game. On the other hand, if I get a WORKING Dedicated server, I can leave while I go eat, easily come back in the game etc.